US4370456AExpiredUtility

Catalyst composition for copolymerizing ethylene

79
Assignee: UNION CARBIDE CORPPriority: Nov 23, 1981Filed: Nov 23, 1981Granted: Jan 25, 1983
Est. expiryNov 23, 2001(expired)· nominal 20-yr term from priority
Inventors:Kathleen F. George
Y10S526/901C08F 210/00
79
PatentIndex Score
41
Cited by
2
References
38
Claims

Abstract

Ethylene copolymers having improved resistance to pinstriping and gel streaking when extruded into film can be produced by continuously copolymerizing ethylene with one or more higher alpha olefin monomers in a low pressure gas phase reaction with a catalyst composition prepared by forming a precursor composition from a magnesium compound, titanium compound, and electron donor compound; diluting said precursor composition with a silica support which has been treated with a dialkylzinc compound; and activating the diluted precursor composition with an organoaluminum compound.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
       1. A continuous process for producing ethylene copolymers containing at least 90 mol percent of ethylene and no more than 10 mol percent of one or more alpha olefins containing from 3 to 8 carbon atoms, said copolymers being produced in granular form and having a density of from 0.91 g/cm 3  to 0.94 g/cm 3 , which comprises contacting a mixture of ethylene and at least one alpha olefin containing from 3 to 8 carbon atoms, at a temperature of from 30° C. to 105° C. and a pressure no greater than 1000 psi, in a gas phase reaction zone, with particles of a catalyst system comprising a precursor composition having the formula   Mg.sub.m Ti(OR).sub.n X.sub.p [ED].sub.q       wherein R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms, or COR' wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,   X is selected from the group consisting of Cl, Br, I, and mixtures thereof,   ED is an organic electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones,   m is 0.5 to 56,   n is 0, 1 or 2,   p is 2 to 116, and   q is 2 to 85,   said precursor composition being diluted with a silica support containing from 5 percent by weight to 15 percent by weight of a dialkylzinc compound having the formula   ZnR"R"'       wherein R" and R"' are alkyl radicals containing from 1 to 12 carbon atoms,   and said precursor composition being completely activated with an organoaluminum activator compound having the formula   Al(R"").sub.d X'.sub.e H.sub.f       wherein X' is Cl or OR""',   R"" and R""' are saturated hydrocarbon radicals containing from 1 to 14 carbon atoms,   e is 0 to 1.5,   f is 0 or 1, and   d+e+f=3,   said activator compound being employed in an amount such as to provide a total aluminum:titanium molar ratio in said reaction zone of from 10:1 to 400:1.   
     
     
       2. A process as in claim 1 wherein said precursor composition is mechanically mixed with the silica support and the blended mixture contains from 3 percent by weight to 50 percent by weight of the precursor composition. 
     
     
       3. A process as in claim 1 wherein the silica support is impregnated with the precursor composition and the impregnated support contains from 3 percent by weight to 50 percent by weight of the precursor composition. 
     
     
       4. A process, as in claim 1, 2 or 3 wherein X and X' are Cl, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       5. A process as in claim 4 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       6. A process as in claim 5 wherein the dialkylzinc compound is diethylzinc. 
     
     
       7. A process as in claim 1, 2 or 3 wherein the precursor composition is diluted with a silica support containing from 6 percent by weight to 8 percent by weight of the dialkylzinc compound. 
     
     
       8. A process as in claim 7 wherein X and X' are Cl, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       9. A process as in claim 8 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       10. A process as in claim 9 wherein the dialkylzinc compound is diethylzinc. 
     
     
       11. A precursor composition suitable as a component of a catalyst composition capable of copolymerizing ethylene with higher alpha olefins under a pressure of less than 1000 psi, said precursor composition having the formula   Mg.sub.m Ti(OR).sub.n X.sub.p [ED].sub.q     wherein R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms, or COR' wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,   X is selected from the group consisting of Cl, Br, I, and mixtures thereof,   ED is an organic electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones,   m is 0.5 to 56,   n is 0, 1 or 2,   p is 2 to 116, and   q is 2 to 85,   said precursor composition being diluted with a silica support containing from 5 percent by weight to 15 percent by weight of a dialkylzinc compound having the formula   ZnR"R"'       wherein R" and R"' are alkyl radicals containing from 1 to 12 carbon atoms.   
     
     
       12. A composition as in claim 11 wherein said precursor composition is mechanically mixed with the silica support and the blended mixture contains from 3 percent by weight to 50 percent by weight of the precursor composition. 
     
     
       13. A composition as in claim 11 wherein the silica support is impregnated with the precursor composition and the impregnated support contains from 3 percent by weight to 50 percent by weight of the precursor composition. 
     
     
       14. A composition as in claim 11, 12 or 13 wherein X is CL, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       15. A composition as in claim 14 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       16. A composition as in claim 15 wherein the dialkylzinc compound is diethylzinc. 
     
     
       17. A composition as in claim 11, 12 or 13 wherein the precursor composition is diluted with a silica support containing from 6 percent by weight to 8 percent by weight of the dialkylzinc compound. 
     
     
       18. A composition as in claim 17 wherein X is Cl, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       19. A composition as in claim 18 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       20. A composition as in claim 19 wherein the dialkylzinc compound is diethylzinc. 
     
     
       21. A precursor composition as in claim 11, 12 or 13 which has been partially activated with an organoaluminum activator compound having the formula   Al(R"").sub.d X'.sub.e H.sub.f     wherein X' is Cl or OR""',   R"" and R""' are saturated hydrocarbon radicals containing from 1 to 14 carbon atoms,   e is 0 to 1.5,   f is 0 or 1, and   d+e+f=3,   said activator compound being employed in an amount such as to provide the precursor composition with a molar ratio of activator compound:electron donor of up to 1.4:1.   
     
     
       22. A composition as in claim 21 wherein X and X' are Cl, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       23. A composition as in claim 22 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       24. A composition as in claim 23 wherein the dialkylzinc compound is diethylzinc. 
     
     
       25. A composition as in claim 21 wherein the precursor composition is diluted with a silica support containing from 6 percent by weight to 8 percent by weight of the dialkylzinc compound. 
     
     
       26. A composition as in claim 25 wherein X and X' are Cl, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       27. A composition as in claim 26 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       28. A composition as in claim 27 wherein the dialkylzinc compound is diethylzinc. 
     
     
       29. A process for preparing a precursor composition suitable as a component of a catalyst composition capable of copolymerizing ethylene with higher alpha olefins under a pressure of less than 1000 psi which comprises (A) forming a precursor composition of the formula   Mg.sub.m TI(OR).sub.n X.sub.p [ED].sub.q       wherein R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms, or COR' wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,   X is selected from the group consisting of Cl, Br, I, and mixtures thereof,   ED is an organic electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones,   m is 0.5 to 56,   n is 0, 1 or 2,   p is 2 to 116, and   q is 2 to 85,   by dissolving a titanium compound and a magnesium compound in a liquid organic electron donor compound so as to form a solution of said precursor composition in said electron donor compound,   said titanium compound having the structure Ti(OR) a  X b  wherein a is 0, 1 or 2, b is 1 to 4 inclusive, and a+b=3 or 4,   said magnesium compound having the structure MgX 2 ,   said titanium compound, said magnesium compound, and said electron donor compound being employed in such amounts as to satisfy the values of m, n, p and q, and   (B) diluting said precursor composition with a silica support containing from 5 percent by weight to 15 percent by weight of a dialkylzinc compound having the formula   ZnR"R"'       wherein R" and R"' are alkyl radicals containing from 1 to 12 carbon atoms.   
     
     
       30. A process as in claim 29 wherein said precursor composition is mechanically mixed with the silica support and the blended mixture contains from 3 percent by weight to 50 percent by weight of the precursor composition. 
     
     
       31. A process as in claim 29 wherein the silica support is impregnated with the precursor composition and the impregnated support contains from 3 percent by weight to 50 percent by weight of the precursor composition. 
     
     
       32. A process as in claim 29, 30 or 31 wherein X is Cl, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       33. A process as in claim 32 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       34. A process as in claim 33 wherein the dialkylzinc compound is diethylzinc. 
     
     
       35. A process as in claim 29, 30 or 31 wherein the precursor composition is diluted with a silica support containing from 6 percent by weight to 8 percent by weight of the dialkylzinc compound. 
     
     
       36. A process as in claim 35 wherein X is Cl, [ED] is tetrahydrofuran, n is 0, m is 1.5 to 5, p is 6 to 14, and q is 3 to 10. 
     
     
       37. A process as in claim 36 wherein R" and R"' are alkyl radicals containing from 1 to 6 carbon atoms. 
     
     
       38. A process as in claim 37 wherein the dialkylzinc compound is diethylzinc.

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